MOSCOW — An Armenian member of the Soviet Congress says he will starve himself to death unless the government puts an end to martial law in the disputed Nagorno-Karabakh region.

"I will starve to death if nothing is done to fulfill our demands," Sos Sarkisyan, 61, an actor and member of the Congress of People's Deputies, said in the Moscow hotel room where five Armenian political figures have been on a hunger strike since last week. "If the world does not lift its voice to protest what is happening in Karabakh, it will become a second Beirut."

The five Armenians are protesting military rule declared by President Mikhail S. Gorbachev in January over Nagorno-Karabakh, the small, mountainous, mostly Armenian enclave in the neighboring republic of Azerbaijan.

Soviet troops have been in Nagorno-Karabakh for 2 1/2 years, since the outset of violent clashes between Christian Armenians and Muslim Azerbaijanis. The troops support armed Azerbaijani militias who have imposed a blockade of the region, and Armenians say the presence of the Soviet troops constitutes an occupation.

"We are completely cut off from the rest of the world," Zori Balayan, 55, a writer and member of the Congress of People's Deputies from Nagorno-Karabakh, said on the 12th day of the hunger strike. "We have no television, no telephone connections or telegrams. Nagorno-Karabakh is like an island, a little Christian island surrounded by Muslims."

Armenians argue that the land, at some points just five miles from their border, was taken from them in the 1920s by the dictator Josef Stalin and should be returned. The Azerbaijanis are determined to retain control over it.

The hunger strikers want the central government to return power to the locally elected leaders of Nagorno-Karabakh.

"I've already tried all other measures," Balayan said. "I spoke out repeatedly at parliamentary sessions, wrote articles in newspapers, sent telegrams to President Gorbachev, but none of this had any effect."

Balayan, who had a heart operation last year in Los Angeles, was warned by doctors that a hunger strike would be dangerous to his health. Still, he was the first to begin the protest.

Four of the five hunger strikers are at the Hotel Moskva, the quarters of Soviet lawmakers in Moscow. They were drinking only distilled water or mineral water.

Four are members of the Congress of People's Deputies, the national Parliament, and the fifth is chairman of the Nagorno-Karabakh regional council. Sarkisyan addressed the California Legislature in Sacramento last spring on the crisis in Nagorno-Karabakh.

Best-known among them is Viktor Ambartsumyan, 82, president of the Armenian Academy of Science. He is regarded as the father of Soviet astrophysics.

On Thursday, the seventh day of his hunger strike, Ambartsumyan grew dizzy and could not rise from his bed. He was taken to a hospital and placed under observation.

"I could not stand by quietly any longer," Ambartsumyan said earlier in a letter to Gorbachev. "My only demand is that the elected leaders of Nagorno-Karabakh regain control."

The hunger strikers have fiercely criticized Gorbachev for failing to solve the long-festering dispute over Nagorno-Karabakh.

"From the beginning of the Karabakh movement, I knew Gorbachev could not decide even the most simple questions to ease life in Karabakh," Balayan said. "Gorbachev cannot even break the (Azerbaijanis') blockade around Karabakh."

Gorbachev and leaders of the national Congress sent telegrams to the hunger strikers last weekend urging them to give up their protest.

"The U.S.S.R. Supreme Soviet is urging you to stop the hunger strike and thus create favorable conditions for a constructive settlement of the conflict in Nagorno-Karabakh," Anatoly I. Lukyanov, chairman of the Congress, said in his telegram.

But such appeals have had little impact on the protesters.

"We will not stop our hunger strike until we get what we demand," Balayan said. "Gorbachev has made promises to us over and over again in the past few years, and each time he deceived us. Our people cannot be patient any more."

Tension between Nagorno-Karabakh's 186,000 people and the Azerbaijani Republic's Organizing Committee for Nagorno-Karabakh, which rules the region with the military, has increased recently.

The independent Soviet news service Interfax reported Tuesday that despite the state of emergency in effect in Nagorno-Karabakh, thousands of people demonstrated in Stepanakert, the regional capital, calling for restoration of the local government.

Tanks move through the city's streets almost daily, according to Vachagan Grigoryan, 55, another member of the national parliament who lives in Nagorno-Karabakh. A curfew is enforced from 9 p.m. to 6 a.m., and thousands of troops patrol the city on foot.